1. Technical Field
The present disclosure relates to an operation assisting device and an operation assisting method that assist an operation based on the utterance of a keyword.
2. Description of the Related Art
In recent years, a technique for detecting, when a predetermined keyword is spoken, the keyword and starting a predetermined operation of an apparatus such as activating a system has been widely put to practical use.
Usually, determination of whether or not the keyword is spoken (hereinafter, called “keyword determination”) is performed by calculating an evaluation value (score) indicating a plausibility (hereinafter, called a likelihood) that a keyword is included in a spoken voice and determining whether or not the evaluation value is greater than or equal to a predetermined threshold value. The evaluation value is calculated by, for example, voice recognition processing for the spoken voice.
However, in some cases, even if a keyword is actually spoken, an ambient sound, unintelligibility of utterance, or the like causes the evaluation value to be low. In this case, such a state occurs that it is difficult to operate an apparatus in spite of the user trying to speak the keyword (hereinafter, called “operation failure”).
Therefore, a technique in which similarity between a keyword and a spoken voice is calculated and it is determined that the keyword is spoken in a case where the calculated similarity falls within a predetermined range is described in, for example, Japanese Unexamined Patent Application Publication No. 11-231896. According to such a technique, it is possible to reduce the occurrence of an operation failure.
However, in a case where a user forgets a keyword or remembers a wrong keyword, similarity between the keyword and a spoken voice becomes low. Therefore, in the related art, it is difficult to avoid the operation failure, and there is a possibility that an operation based on a keyword utterance (hereinafter, called a “keyword utterance operation”) is disabled.